The present invention relates to an improved hypodermic syringe assembly which is designed to be relatively simple and inexpensive to manufacture and package, so as to be disposable after one-time use, and which is particularly suited to being packaged and sold with a medicament-filled ampule seated in the syringe assembly ready for use.
Numerous disposable hypodermic syringes have been proposed over the years which have a fixed needle or cannula at the forward end of the syringe barrel and a plunger inserted into the syringe barrel through the rearward end thereof with the plunger being movable within the barrel to aspirate medicament into the syringe through the needle and to expel medicament out of the syringe through the needle for making hypodermic injections. Further, both reusable and disposable hypodermic syringes have been designed whereby the syringe barrel may be either side-loaded or end-loaded with a medicament-filled ampule having a stopper or diaphragm which is pierceable by the sharpened butt end of the needle mounted at the forward end of the syringe barrel. In such ampule-syringe assemblies the plunger either moves the ampule with respect to a stopper to expel medicament from the ampule or moves a stopper with respect to the ampule to expel the medicament.
There remains a need for a pre-packaged, pre-sterilized, disposable hypodermic syringe assembly with a medicament-filled ampule seated within the syringe barrel substantially ready-for-use, but with the syringe protected against accidental expulsion of the medicament while the syringe is in its packaging.